3D printing and robotics have been evolving in harmony over the last few years, as the improved design possibilities presented by the former have enabled the creation of all kinds of innovative robots for a broad range of applications, drawing inspiration from a variety of sources. The natural world is as valid a source of inspiration as any, and a recent project saw a 3D printed robotic version of a unique type of fish being developed, to hopefully contribute towards the study of marine life. It was a collaborative project between Beihang University, Harvard University, and Boston College.

The robot was based on the remora, otherwise known as the slender sharksucker. This marine creature has a special suction disc on its head, which it uses to hitchhike on larger aquatic beasts such as whales, sharks and turtles, as they twist and turn and swim at speeds that are often upwards of 1.5 metres per second. It can simultaneously move around and feed on the larger animals’ food scraps, faeces, and microscopic crustaceans that gather on their surface, without expending much of its own energy.

Saving energy in this way is also an important aspect of robotics design, particularly for robots that are intended to move underwater. The majority of aquatic robots move incredibly slowly, with a robotic stingray that moves at 6 centimetres per second being one of the fastest developed so far. This is what drove the research team to copy the remora’s strategy, developing a robot that uses suction to hitch a lift on larger sea creatures.

Produced using 3D printing technology and laser cutting techniques, the robot comprises a fin and a suction pad with 1000 tiny carbon fiber spinules attatchecd to it. These spinules can be lowered or raised to help the suction pad grip to whatever surface it is in contact with.

In tests, the deep sea-derived robot was able to withstand pull-off forces that were equivalent of 340 times its own weight, lifting weights up to 100 pounds. The robot was attatched to a variety of rough and smooth surfaces to test its adhesion capabilities underwater, and it successfully gripped to shark skin, Plexiglas and a rubber-like material. Out of water, it could also attatch itself to wood, cardboard and even a smartphone.

The next phase in the research will be an attempt to attatch the robot to a real-life shark, whale, or dolphin, and to see how it fares as they swim around. This will lead to the eventual goal of the research, which is to develop more advanced ways of recording data by tagging these marine animals and tracking their behaviour. Sensors currently used for this purpose are at best ineffective, as they tend to fall off too early to gather any relevant results. Some of the existing tracking devices have also been known to cause harm to the animals. Another potential application for this underwater suction technology would be for robots that are used to maintain underwater infrastructure, such as submerged oil pipes.